BTRFS info (device loop0): clearing compat-ro feature flag for FREE_SPACE_TREE (0x1) BTRFS info (device loop0): clearing compat-ro feature flag for FREE_SPACE_TREE_VALID (0x2) BTRFS info (device loop0): checking UUID tree ====================================================== WARNING: possible circular locking dependency detected 6.2.0-rc6-syzkaller-00083-ge7368fd30165 #0 Not tainted ------------------------------------------------------ syz-executor.0/2393 is trying to acquire lock: ffff8880794a1e08 (btrfs-tree-01){++++}-{3:3}, at: __btrfs_tree_read_lock fs/btrfs/locking.c:135 [inline] ffff8880794a1e08 (btrfs-tree-01){++++}-{3:3}, at: btrfs_tree_read_lock fs/btrfs/locking.c:141 [inline] ffff8880794a1e08 (btrfs-tree-01){++++}-{3:3}, at: btrfs_read_lock_root_node+0x2b4/0x400 fs/btrfs/locking.c:280 but task is already holding lock: ffff88807e77fa28 (btrfs-tree-00){++++}-{3:3}, at: __btrfs_tree_read_lock fs/btrfs/locking.c:135 [inline] ffff88807e77fa28 (btrfs-tree-00){++++}-{3:3}, at: btrfs_tree_read_lock+0x1e/0x40 fs/btrfs/locking.c:141 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (btrfs-tree-00){++++}-{3:3}: lock_acquire+0x182/0x3c0 kernel/locking/lockdep.c:5668 down_read_nested+0x3c/0x50 kernel/locking/rwsem.c:1634 __btrfs_tree_read_lock fs/btrfs/locking.c:135 [inline] btrfs_tree_read_lock+0x1e/0x40 fs/btrfs/locking.c:141 btrfs_search_slot+0x1512/0x31f0 fs/btrfs/ctree.c:2249 btrfs_init_root_free_objectid+0x12d/0x320 fs/btrfs/disk-io.c:5373 btrfs_init_fs_root fs/btrfs/disk-io.c:1561 [inline] btrfs_get_root_ref+0x6a9/0xe00 fs/btrfs/disk-io.c:1765 btrfs_get_fs_root fs/btrfs/disk-io.c:1817 [inline] open_ctree+0x2863/0x2ee0 fs/btrfs/disk-io.c:3886 btrfs_fill_super+0x1c6/0x2d0 fs/btrfs/super.c:1151 btrfs_mount_root+0x885/0x9a0 fs/btrfs/super.c:1520 legacy_get_tree+0xea/0x180 fs/fs_context.c:610 vfs_get_tree+0x88/0x270 fs/super.c:1489 fc_mount fs/namespace.c:1149 [inline] vfs_kern_mount+0xc9/0x160 fs/namespace.c:1179 btrfs_mount+0x3d3/0xbc0 fs/btrfs/super.c:1580 legacy_get_tree+0xea/0x180 fs/fs_context.c:610 vfs_get_tree+0x88/0x270 fs/super.c:1489 do_new_mount+0x289/0xad0 fs/namespace.c:3145 do_mount fs/namespace.c:3488 [inline] __do_sys_mount fs/namespace.c:3697 [inline] __se_sys_mount+0x2d3/0x3c0 fs/namespace.c:3674 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #0 (btrfs-tree-01){++++}-{3:3}: check_prev_add kernel/locking/lockdep.c:3097 [inline] check_prevs_add kernel/locking/lockdep.c:3216 [inline] validate_chain+0x1898/0x6ae0 kernel/locking/lockdep.c:3831 __lock_acquire+0x1292/0x1f60 kernel/locking/lockdep.c:5055 lock_acquire+0x182/0x3c0 kernel/locking/lockdep.c:5668 down_read_nested+0x3c/0x50 kernel/locking/rwsem.c:1634 __btrfs_tree_read_lock fs/btrfs/locking.c:135 [inline] btrfs_tree_read_lock fs/btrfs/locking.c:141 [inline] btrfs_read_lock_root_node+0x2b4/0x400 fs/btrfs/locking.c:280 btrfs_search_slot_get_root fs/btrfs/ctree.c:1779 [inline] btrfs_search_slot+0x502/0x31f0 fs/btrfs/ctree.c:2101 btrfs_lookup_inode+0xc0/0x490 fs/btrfs/inode-item.c:412 btrfs_read_locked_inode fs/btrfs/inode.c:3983 [inline] btrfs_iget_path+0x289/0x1490 fs/btrfs/inode.c:5799 btrfs_search_path_in_tree_user fs/btrfs/ioctl.c:1960 [inline] btrfs_ioctl_ino_lookup_user+0x700/0xf10 fs/btrfs/ioctl.c:2104 btrfs_ioctl+0xb91/0xc10 fs/btrfs/ioctl.c:4668 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(btrfs-tree-00); lock(btrfs-tree-01); lock(btrfs-tree-00); lock(btrfs-tree-01); *** DEADLOCK *** 1 lock held by syz-executor.0/2393: #0: ffff88807e77fa28 (btrfs-tree-00){++++}-{3:3}, at: __btrfs_tree_read_lock fs/btrfs/locking.c:135 [inline] #0: ffff88807e77fa28 (btrfs-tree-00){++++}-{3:3}, at: btrfs_tree_read_lock+0x1e/0x40 fs/btrfs/locking.c:141 stack backtrace: CPU: 1 PID: 2393 Comm: syz-executor.0 Not tainted 6.2.0-rc6-syzkaller-00083-ge7368fd30165 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1b1/0x290 lib/dump_stack.c:106 check_noncircular+0x2cc/0x390 kernel/locking/lockdep.c:2177 check_prev_add kernel/locking/lockdep.c:3097 [inline] check_prevs_add kernel/locking/lockdep.c:3216 [inline] validate_chain+0x1898/0x6ae0 kernel/locking/lockdep.c:3831 __lock_acquire+0x1292/0x1f60 kernel/locking/lockdep.c:5055 lock_acquire+0x182/0x3c0 kernel/locking/lockdep.c:5668 down_read_nested+0x3c/0x50 kernel/locking/rwsem.c:1634 __btrfs_tree_read_lock fs/btrfs/locking.c:135 [inline] btrfs_tree_read_lock fs/btrfs/locking.c:141 [inline] btrfs_read_lock_root_node+0x2b4/0x400 fs/btrfs/locking.c:280 btrfs_search_slot_get_root fs/btrfs/ctree.c:1779 [inline] btrfs_search_slot+0x502/0x31f0 fs/btrfs/ctree.c:2101 btrfs_lookup_inode+0xc0/0x490 fs/btrfs/inode-item.c:412 btrfs_read_locked_inode fs/btrfs/inode.c:3983 [inline] btrfs_iget_path+0x289/0x1490 fs/btrfs/inode.c:5799 btrfs_search_path_in_tree_user fs/btrfs/ioctl.c:1960 [inline] btrfs_ioctl_ino_lookup_user+0x700/0xf10 fs/btrfs/ioctl.c:2104 btrfs_ioctl+0xb91/0xc10 fs/btrfs/ioctl.c:4668 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f3a0e88c0c9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f3a0f661168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f3a0e9abf80 RCX: 00007f3a0e88c0c9 RDX: 00000000200000c0 RSI: 00000000d000943e RDI: 0000000000000004 RBP: 00007f3a0e8e7ae9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffeeba9223f R14: 00007f3a0f661300 R15: 0000000000022000